For many years, articles bearing customized designs, or personalized with intitials, names, and the like, have been very popular with the public. Tee-shirts displaying the name of the wearer, catchy slogans, names of popular personages and like designs have become commonplace. Typically, the articles are personalized at the point of purchase, the purchaser choosing a particular design and the vendor transferring it immediately to the article selected. One method for decorating such articles comprises the use of sublimation transfer techniques involving the printing of a design on a paper backing sheet by conventional printing techniques with sublimation inks, and transferring such designs under heat and pressure to a substrate, usually a fabric. During the process, the sublimable dyes vaporize from the backing sheet and condense on the cooler substrate to form a brilliant image. In the case of a billed cap, for example, the process is accomplished by placing the cap on a curved anvil lined with a thin layer of sponge. The front surface of the decal is placed on the cap, and the design is transferred through the application of the heat and pressure produced by contacting the back of the decal with an arcuate pressure foot. In the case of a tee-shirt, the process is similar, except that the pressure foot is flat.
In addition to imprinting relatively flat, fibrous articles, there is also a considerable demand for decorating and personalizing curvilinear and other shapes made from inorganic materials, for instance, vitreous and ceramic articles. The personalization of tiles, tumblers, mugs, and similar objects has become especially popular. Such decorating is frequently done by means of decals prepared with silk-screening methods. After preparation, the design is freed from the backing paper by immersion in water, following which the decal is carefully slipped onto the object to be decorated, and the latter is then glazed and fired in a kiln. While the process produces a very durable design, the process is labor intensive, expensive, and it is inappropriate for point-of-sale use.
In an effort to overcome the deficiencies of the process described, an effort has been made to adapt the sublimation transfer process for use with ceramic materials, since it is quicker, less expensive, and lends itself to use at the point of sale. Adaptation of the sublimation process has been achieved by coating the article to be decorated with a thin film of a polymeric material capable of receiving and retaining the sublimation dyes. While the adaptation has met with some success, no device has yet been devised which permits the sublimation decals to be inexpensively and rapidly applied to ceramic articles with varying curved surfaces. A prior art device presently being used is severely limited with respect to the curvature and diameters of the cylindrical substrates that it can accept, and the device requires undesirably long cycle times. Furthermore, the surface area of the article to which the design can be transferred is restricted.